1. Field of the Invention
This invention generally relates to a magnetic recording and reproducing device and particularly to a floppy disc device for use with a double-sided floppy disc. More specifically, the present invention relates to a structure for supporting a magnetic head such that the head can follow the movement of a flexible floppy disc properly.
2. Description of the Prior Art
Prior art double magnetic head supporting structures may be generally categorized into four groups as follows:
(1) Cantilevered system
In this system, both of magnetic heads are mounted at the free ends of respective cantilevered leaf springs as disclosed in Japanese Patent Publication No. 56-6058 published for the purpose of oppositions, so that the magnetic heads follow the movement of a floppy disc quite well, but there are such disadvantages as easiness in off-tracking and difficulty in assemblage.
(2) One side magnetic head fixed system
As disclosed in Japanese Patent Laid-open Publication No. 54-34221, one of paired magnetic heads is fixedly provided with the other magnetic head mounted at the free end of a movable arm through a gimbal spring and the fixedly provided head is so positioned to slightly lift the floppy disc with the movable head pressed against the fixedly provided head with the floppy disc sandwiched therebetween. This system is easy to assemble and off-tracking does not take place easily. However, the heads do not follow the movement of floppy disc as much as desired. If the heads are made larger in weight so as to allow the heads to follow the movement of the floppy disc more closely, a load against the floppy disc increases which would then cause an increased wear.
(3) Gimbal spring one point pivot supporting system
As disclosed in Japanese Patent Laid-open Publication No. 54-133312, both of magnetic heads are mounted at the center of respective gimbal springs, each of which is supported by a pivot in point contact with the back surface of gimbal spring at the center thereof. In this system, the heads follow the movement of the floppy disc closely and easiness resides in assemblage. However, off-tracking takes place relatively easily, so that this system is not applicable for a disc of high density, which has an increased number of tracks per unit size.
(4) Gimbal spring two point pivot supporting system
As disclosed in Japanese Patent Laid-open Publication No. 57-167164, this is the system in which both of magnetic heads are mounted on respective gimbal springs at the center thereof with one of the gimbal springs being supported by a single pivot, which is in point contact with and at the center of the back side surface of the corresponding gimbal spring, and the other gimbal spring being supported by a double pivot, which is in point contact with and at the center of the corresponding gimbal spring. In this system, off-tracking is less likely to occur, but the heads do not follow the movement of the floppy disc as much as desired because the degree of freedom for the heads is rather limited.